When a fuel, e.g. coal, oil, peat and waste, is combusted in a combustion plant, e.g. a power plant, a hot process gas is generated. Such a hot process gas, often referred to as a flue gas, contains, among other components, carbon dioxide (CO2). Release of components such as carbon dioxide to the atmosphere has negative effects on the environment. These negative environmental effects have been widely recognized, and have resulted in the development of processes adapted for removing carbon dioxide from the hot process gas generated in the combustion of the above mentioned fuels.
WO 2006/022885 relates to a process for absorbing carbon dioxide from a flue gas. The process comprises treatment of the flue gas by means of conventional air pollution control processes, such as by means of particulate collectors, NOx and SO2 control, acid mist capturing devices etc. Following conventional air pollution control processes, the flue gas has a temperature of about 40-70° C. The flue gas is subsequently cooled down to, preferably, 5-25° C. by means of direct contact cooling, wherein the flue gas is cooled by means of cold water. Following cooling, the flue gas is brought to a CO2 absorber, in which the flue gas is brought into contact with a low temperature ammoniated solution having a low carbon dioxide content. The carbon dioxide of the flue gas is absorbed into the ammoniated solution, and a clean flue gas, containing very small amounts of pollutants and carbon dioxide, leaves the CO2 absorber. The carbon dioxide rich ammoniated solution is regenerated in a regenerator, in which the carbon dioxide is desorbed, at a temperature of about 120-200° C. and under high pressure between 8-25 bar, to form a concentrated carbon dioxide rich stream. This carbon dioxide rich gas stream is, after being compressed, generally sent to storage.